If everything aeronautical seemed possible in the heady post-war jet age, some aircraft designs found where the limitations were.
The Convair F2Y Sea Dart was one of four delta-wing jets in design or production by that San Diego company in the 1950s. Convair embraced the delta planform as its ticket to supersonic performance.
But early supersonic jet fighters and the restrictions of aircraft carrier decks were problematical, and one alternative was to create supersonic seaplane fighters for the U.S. Navy.
Anyone who has ever skipped a flat stone across a pond knows the physics involved in a planing surface that, when moving fast enough, does not sink beneath the waves. Hydro skis leveraged that phenomenon into flat plates that could keep a moving aircraft skimming on top of the water.
Convair amalgamated hydro skis, a delta wing, and two turbojets into a floating fighter that could get up on extendable skis and take off from a bobbing start on the ocean’s surface.
The Sea Dart was said to be theoretically capable of operations from snow or ice as well. During its test program at San Diego, the F2Y used small wheels on each hydro ski and the lower aft fuselage to permit it to taxi up and down a seaplane ramp.
The idea of a supersonic Navy jet fighter that was independent of aircraft carriers looked attractive.
When at rest on the sea surface, the Sea Dart floated low in the water, its delta wing nearly awash at the trailing edge. As the two Westinghouse jet engines were throttled up, the F2Y gained speed while floating on its hull until sufficient forward motion was achieved to extend the hydro skis and rise into the planing position. From here, the jet’s vastly decreased water friction made takeoff possible.
When the intended J46 jet engines were not ready, the experimental Sea Dart flew with a pair of lower-powered J34s in 1953. Even when J46s were installed, the Sea Dart lacked area-rule fuselage design that could have enhanced supersonic performance. It required a shallow dive to fly faster than the speed of sound, yet this remains a benchmark for any seaplane.
Armament for proposed operational Sea Darts would have included 20-mm cannons and different types of air-to-air missiles.
Tragedy shook the Sea Dart effort on Nov. 4, 1954, when Sea Dart number 135762 came apart in flight over San Diego Bay during a demonstration flight for officials and media. Convair pilot Charles E. Richbourg died from injuries he received.
The rapid advancement of all kinds of aeronautical technologies overtook the Sea Dart even as it tried to push the state of the art with its own design innovations.
The perceived problems of hosting supersonic jets on aircraft carriers were lessened with devices ranging from powerful new steam catapults pioneered by the British to innovative wing and flap designs like the variable incidence wing of the F8U Crusader for the U.S. Navy.
It has been reported that one engineering faction at Convair argued for making the F2Y a more conventional shipboard design, but lost out to the hydro ski proponents.
As a test aircraft, the Convair Sea Dart flew as late as 1957, but its use as an operational jet fighter never happened. Five airframes were built. One was lost in the crash, and the other four survive on display as this is written.
I was next to the water and saw the sequence of the crash of the “Sea Dart” directly off North Island adjacent to where it hit the water. I did not see anyone around for help. I turned around and sighted the tower and started to frantically wave my arms for personnel to see me pointing toward the point of impact.
Aircraft carrier design and technology made the Sea Dart unnecessary. But the idea is sound.
I wonder what modern computer design programs would do for design and modeling if designs could be “sea and flight tested” with software in a lab.
Perhaps a college competition could test ideas. A seaplane VTOL that could divert some of the fan air from a modern engine to break the water drag might be interesting?
Even an EAA build with help from a manufacturer or someone such as Burt Rutan?
Jim Bede would have done it!